Editing Alliant Techsystems (section)

====Atlas V====
{{Main|Atlas V}}
ATK entered the competition to replace the Russian-made rocket engine on the Atlas V rocket in September 2014. The Atlas V is used to launch most U.S. military satellites. ATK entered the competition in response to a request for proposals from the Air Force Space and Missile Defense Center issued in 2013 for the RD-180 rocket engine. ATK already supplies rocket engines used in heavier version of the Atlas V. ATK says that solid rocket motors are more reliable and deliver more thrust. ATK said, "Solid rocket motors are optimal for first-stage performance as they provide high lift-off thrust, allowing for more payload margin. They also require less ground and launch infrastructure, resulting in fewer launch scrubs."<ref>{{cite web|url=http://defensesystems.com/articles/2014/10/01/atk-to-compete-to-replace-russian-rocket-engine.aspx|title=ATK enters competition to replace Russian rocket engine -- Defense Systems|access-date=June 12, 2015}}</ref> The RD-180 engines use kerosene for fuel. The request from the Air Force occurred due to concerns about whether the RD-180 would be available in the future due to increasing tensions with Russia.<ref>{{cite web|url=http://www.spacenews.com/article/military-space/41966atk-urges-air-force-to-consider-solids-as-it-weighs-rd-180-replacement|archive-url=https://archive.today/20141006194948/http://www.spacenews.com/article/military-space/41966atk-urges-air-force-to-consider-solids-as-it-weighs-rd-180-replacement|url-status=dead|archive-date=October 6, 2014|title=ATK Urges Air Force To Consider Solids as It Weighs RD-180 Replacement|work=SpaceNews.com|access-date=June 12, 2015}}</ref>